today more than half a million tandem jumps in the u.s. alone. >> something like skate boarding was in the '70s. look how well it's accepted. yeah. we'll be there some day. >> reporter: so far only al few hundred people across the country signed up to par pr take partake in one of the world's most dangerous sports. >> three, two, one -- zero! >> oh, my -- >> reporter: but if all the reviews are similar to this -- >> that's awesome! >> reporter: the risks may be well worth the reward. >> i love you, honey! >> oh, man. >> that's nice. alex is here at the table. i'm wondering if those who love and care for you know you do this? >> i tell my mom after. >> you looked like you hit the ground hard there? >> it's a very dangerous sport. the main thing, you only have a few seconds. not much reaction time. skydiving, 45 seconds if something goes wrong. here, not much. also winds can pick up. people jumping off cliffs and stuff like that can get pushed against that. >> even though doing it in tandem with somebody who's done it many, many times. >> ye